ARCTOS 675 ELECTROVAC DIGITAL QUARTZ LCQ LCD 1974
This is the second German LCQuartz 675 developed in 1974 roughly a year later after the LCQ575 by the same team of companies. It can be considered an upgrade of the previous model as many parts are identical. From the outside they both look alike so you need to observe the dial mask which indicates additional functions of date+second on the 675. This review shows a few more details as it was a bit easier to disassemble the time-setting assembly without risk of damage. The display is fitted the same way with a spring frame providing even pressure on the glass. It must be carefully released from the right side. In comparison to Optel watches the German LCQ's hardly ever show any aging to the liquid crystal display nor to the graphite rubber pads which tend to dissolve on the BWC DSM watches.
The modules are soldered by hand with a majority of American parts and chips provided by Solid State Scientific. The smaller driver chip is the same 5425 on both the 575 and 675 modules however the later version has a main chip numbered 5442F versus 5424F on the earlier 575 without date and seconds. The chip feet are very long and exposed with only a sticker insulating them from the battery. Extreme caution must be applied so that these feet are not damaged what would result in a dead watch or missing segments on the display...and that would not be repairable. Time-setting is also performed the same way on both types of watches with the only difference of additional seconds displayed by pushing the crown. Setting of all functions is also a bit more complex on the 675.
The setting assemby has been redesigned on the 675 with the slider made of fibre-glass instead of a pertinax substrate. There are two small brass pins in that white slider which connect corresponding traces with the visible metal levers. Unfortunately years of use and time-setting (sliding) has resulted in small brass particles being left on the substrate surface underneath the slider. In order to release the slider and clean the module you need to desolder the entire setting assembly. This module had internal shorts with the display always going blank upon pulling out the crown. Cleaning the setting assembly from those tiny brass particles did not improve the functionality of the watch but it became somewhat more stable when the display was constantly lit and the crown was not moved.
Keywords: arctos lcd, arctos 675, provita, electrovac, bwc
Market value: 100-350$ (version, condition, box)